Characterization of chemokine receptor expression and cytokine production in circulating CD4+ T cells from patients with atopic dermatitis: up-regulation of C-C chemokine receptor 4 in atopic dermatitis.

Summary Background Th2 and Th1 cells have been suggested to express CCR3/CCR4 and CCR5/CXCR3, respectively. Objective We examined CCR3, CCR4, CCR5 and CXCR3 expression and cytokine production in peripheral blood CD4+ T cells from patients with atopic dermatitis (AD), which has been postulated to be a Th2-type cell-mediated disease, and then analysed the possible correlation between these values and the levels of several clinical parameters. Methods Intracellular cytokine production and chemokine receptor expression in peripheral blood CD4+ T cells from 40 AD patients and 20 sex- and age-matched healthy control subjects were studied by flow cytometry. Results The frequencies of IL-4- and IL-13-producing CD4+ T cells from patients with AD were significantly higher than those from healthy control subjects (IL-4:3.9 ± 2.1% vs. 1.6 ± 0.7%, P = 0.0005, IL-13:4.0 ± 2.1% vs. 1.8 ± 0.8%, P = 0.0023), whereas the frequencies of IL-2- and IFN-γ-producing CD4+ T cells were significantly decreased in AD patients (IL-2:38.1 ± 10.3% vs. 51.3 ± 6.3%, P = 0.0003, IFN-γ: 9.9 ± 3.5% vs. 26.4 ± 4.6%, P < 0.0001). The percentage of CCR4+ cells in CD4+ CD45RO+ T cells in AD patients was significantly higher than that in healthy control subjects (24.4 ± 8.0% vs. 10.9 ± 2.3%, P < 0.0001) and was correlated positively with the total serum IgE, serum lactic dehydrogenase (LDH) level, eosinophil number, eruption score, and IL-4 and IL-13 secretion in CD4+ T cells, and inversely with IL-2 and IFN-γ secretion in CD4+ T cells. In contrast, CCR3 was not detected on circulating CD4+ T cells even in AD patients. On the other hand, the percentage of CCR5+ or CXCR3+ cells in CD4+ CD45RO+ T cells in AD patients was significantly decreased (CCR5:23.2 ± 7.0% vs. 28.4 ± 5.4%, P = 0.023, CXCR3:29.9 ± 11.4% vs. 38.5 ± 6.7%, P = 0.028) and was positively correlated with eruption score (P < 0.05). Multiple regression analyses showed that the percentage of CCR4 expression highly correlated with serum IgE, LDH, eosinophil number and eruption in AD patients. Conclusion CCR4+ cells might be involved in the aetiopathogenesis of AD.